by What if you lost all of your bitcoins tomorrow? What would you do?
Let me stress this point:
“If you don’t own your private key, you don’t own your bitcoins.”
Yes, you read that right.
Even the most knowledgeable man on Bitcoin says:
“The private key must remain secret at all times because revealing it to third parties is equivalent to giving them control over the bitcoins secured by that key. The private key must also be backed up and protected from accidental loss, because if it’s lost it cannot be recovered and the funds secured by it are forever lost, too.”
― Andreas M. Antonopoulos, Mastering Bitcoin: Unlocking Digital Cryptocurrencies
In my earlier guide on Bitcoin wallets, I extensively used two terms: Private Address (or key) and Public Address (or key). These keys are what make Bitcoin the safest and most widely used cryptocurrency.
Let us look at an example to understand private and public keys.
Consider a mailbox where you receive your physical mail.
It has a unique and specific number (an address). If someone has to deliver you a letter, he/she must know your house/flat number to deliver it.
And as the receiver, you have a private address (or key) to unlock the mailbox and collect your belongings.
In real life, do you give your keys to someone unknown?
- No. Of course not.
You always keep track of your key and don’t jeopardize the contents inside of your mailbox.
Similarly, like your house/flat number, anyone in the Bitcoin world can know your public address (Bitcoin address) to send you bitcoins. And to unlock (spend/send) those bitcoins, you would require your private address (or key), for which you need to take full responsibility, just like the keys of the mailbox.
I feel that understanding the underlying technical aspect of keys is important so that you remain better informed and educated enough to take care of them.
In the next section, I will tell some basic technical aspects of these keys.
Page Contents
What is Bitcoin Private Key?
A private key is a secret, alphanumeric password/number used to spend/send your bitcoins to another Bitcoin address. It is a 256-bit long number that is picked randomly as soon as you make a wallet.
The degree of randomness and uniqueness is well defined by cryptographic functions for security purposes.
This is how the Bitcoin private key looks:
5Kb8kLf9zgWQnogidDA76MzPL6TsZZY36hWXMssSzNydYXYB9KF
What is a Public Address (or key)?
This is another alphanumeric address/number which is derived from private keys only by using cryptographic math functions.
It is impossible to reverse engineer and reach the private key from which it was generated.
This is the address used to receive bitcoins publicly.
This how the Bitcoin public address looks like:
1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm
35RLr51qNvwcr65kma7ucXj8evKHT3SWvP
This address is always seen and broadcasted for receiving bitcoins. Users can make as many public addresses as they want to receive bitcoins.
What are Bitcoin private keys used for?
Private keys are used for making irreversible transactions. Yes, irreversible!
They are the key to spending and sending your bitcoins to anyone and anywhere. This irreversibility is guaranteed by mathematical signatures linked to each transaction whenever we use the private keys to send bitcoins.
And for each transaction, these signatures are unique, even though they are generated from the same private keys. This feature makes them impossible to copy. The user can confidently use the same private key again and again.
Moreover, the signatures are mathematically related to Bitcoin addresses. This math relation helps in confirming that the signatures are only of that particular account holder who wants to transfer bitcoins.
How do we keep private keys safe?
It is OK if you don’t understand the above technical stuff.
You can still use Bitcoin as long as you keep your private keys safe.
These digital keys are crucial in the ownership of bitcoins. These keys are not stored on the Bitcoin network but are created and stored by the file/software (a.k.a. wallet).
A wallet stores these keys. There are many types of wallets out there, and some allow private keys to be stored and guarded by the user.
Some keep the key safe on behalf of the user.
I have explored each type of safety measure for you so that you can choose the most effective wallet according to your needs.
Web and Mobile Wallets
Most of the web and mobile wallet software services in the Bitcoin market store your private key on your behalf on their servers.
They get stored in an encrypted form which only you can decrypt.
iOS Wallets:
Desktop Wallets
Desktop wallets are relatively safe. In such wallets, once you install them on your desktop, you will get your Bitcoin address and private key in a downloadable and importable file.
These importable keys can be made password protected and stored on a memory stick or hard drive.
But once you lose the private key file, you will lose the bitcoins.
I will discuss each of these in detail in upcoming articles.
- Exodus
- Electrum
Here are a few desktop Bitcoin wallets:
Hardware Wallets
Hardware wallets are an electronic invention made to store your private keys offline, away from the vulnerable online environment, so they can’t be hacked.
Some hardware wallets come with security grid cards similar to some debit cards to verify the transaction. Some even have a little digital screen to verify your transactions.
They are tamper-proof and come with a limited user interface. If your device is destroyed, you can retrieve your keys and bitcoins as long as you have a backup code.
Some of the popular hardware wallets are:
Trezor was the first hardware wallet to be launched since the invention of Bitcoin. It is a small device that can be connected via a USB cable to your personal computer. Its fundamental purpose is to store the private keys offline and sign transactions.
Trezor Model T, the latest and most convenient product by the Trezor team, costs about 189 euros. You can order it today on their official website.
Ledger Nano S can be used even on a computer infected with malware. It has two buttons which are needed to be pressed together to sign and confirm a transaction, making it impossible for a hacker to use.
Ledger Nano S also requires the user to create a PIN code on setup. The PIN code helps prevent the loss of bitcoins in case your Nano S gets lost.
It supports Bitcoin, Ethereum, and other popular altcoins and connects with other software wallets like MyCelium. Here is a video to learn more about Ledger Nano S:
Paper Wallets (Cold Storage)
Paper wallets are simply Bitcoin private keys printed on a piece of paper. It can also have the Bitcoin public address printed on it, but not necessarily. Paper wallets are an effective way of storing Bitcoin private keys offline.
They protect the user against potential theft or mishap with the desktop or mobile devices.
These kinds of wallets are also called “cold storage” because the keys are generated offline and never stored online or on a computer.
You can make your paper wallet from bitaddress.org, which is an HTML page specifically for this purpose only.
You can save the HTML page offline and remain disconnected from the internet to generate the keys. They can be printed on paper or stored as a soft copy on a USB or hard drive. Read my previous guide on how to make a Bitcoin paper wallet.
Conclusion
The most important thing in a Bitcoin wallet is your private key, which will prove that the bitcoins you claim are actually yours.
How are you keeping your private keys safe? Let us know what you do in the comments below!! Have a question about Bitcoin Private keys? Feel free to ask in the comment section below.
Here are a few more Bitcoin wallet-related guides that you must read next:
- Highlighting The Difference Between Sweeping & Importing Private Keys
- Why Should You Order 2 Or More Hardware Wallets At The Same Time?
- Security Risks of Mobile, Web & Desktop Bitcoin Wallets [Must Know]
- Best Bitcoin Wallet
- How to get a Bitcoin address?
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About Harsh Agrawal :
An award-winning blogger with a track record of 15+ years. He has a background in both finance and technology and holds bachelors degree in Information technology and engineering.
An international speaker and author who believes in the future of blockchain and the applications of the crypto world.
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Expertise:
Harsh has 15+ years of experience in Fintech and 7+ years in Blockchain and Bitcoin. He has also moderated the panel of Blockchain experts and attended international blockchain events like BTCMiami, Mainnet Messari, and Token2049.
Hi, Nice Tutorial. I have few questions. Please help me.
1. What is the difference between private key and the seed words we get while creating wallet?
2. What will happen if someone just guesses my private key/seed words by hit and trial method?
3. If I have private key, can I use that wallet in any of the client? (Desktop/Mobile/Web/Harware)? Can I open my same wallet in multiple clients also?
4. Does harware wallet require internet to work? If not, how the transaction get processed? If Yes, from where it gets internet connectivity? does not it cause security issue?
Private Key and Seed Words both are the same.
You can use the Seed Words to generate a Private key for yourself as well.
Private Key is a very difficult array of alpha-numeric letters. I don’t think so that it would be easy for any one to randomly hint at a private key. Similarly, seed words are totally weird in their order, it’s not easy for someone to guess the words at first, and then the order of words after that.
Once you have a private key, you can use it to access the wallet in any client. That’s because your coins are stored on the blockchain. Your private key is the only access to them. Client really doesn’t matter once you have your keys, json keystore files and seed words.
About the hardware wallet, it depends on how you want to use it. Whether you want to use it with a desktop wallet or with a web wallet. The internet connection totally depends on your choice, but once the wallet is disconnected from your computer, it does not have any internet access which would leave your funds insecure.
I hope this helps. My answers may not be accurate, but that’s the best I Know.
I still dont understand this thing about private keys? where are they and how to you store them or keep them ? i dont understand,
I have installed bitcoin core and fully synchronized and i have saved my wallet.dat to a usb key.
now what ?
@ James
Hey, private keys are an alphanumeric string which allows you to send/spend your BTCs when you want. In short (Your Bitcoin= Your private keys).
If you using a hosted wallet then you won’t be able to access your private keys.
And if you using a Bitcoin Core then you can export your private keys. Refer this guide for exporting keys.
Would it be possible to know my private keys on Zebpay? If yes,How?
@Siddharth No not possible it’s a hosted exchange.
please give details
sir now i cant find my private key old method of find private key is now disappear in Blockchain wallet then what is method to get my key ?
????
Now they give you seed phrases or seed words that are 12 0r 24 words long. You can generate private keys using that .
I think there’s a way to get your private key using your wallet address and recover your funds, like I’m stuk in such situation where I’m about to loose over 133 BTC…..I need help please. I can share my fund with your legit help.
Hey Bill
Thanks for trusting us. But I am sorry to say that you can’t reach a private key with its public key. If this was possible then Bitcoin would have had zero worth as of now.
For more clarification…
What is a Public Address (or key)?
This is another alphanumeric address/number which is derived from private keys only by using cryptographic math functions.
It is impossible to reverse engineer and reach the private key from which it was generated.
And that’s the beauty of behind the scene cryptographic maths…
And to answer your question of losing 133 BTC…if you would better elaborate us what the scenario is..then we might be able to answer or guide you.
Thanks:)
Did you get help? I can help guide you in the right direction! I do not want a darn thing for it neither.
Bro can you help find the private key of my imported address
Which wallet are you using? Different wallets keep it in different ways.
hi sudhir sir i have a problem, when i recieve btc from someone on my adress then the transaction has the writing of WATCH ONLY . and when i try to spend my funds then it need private key but i never set any private key so pls tell me from where can i get it .
Which wallet?
choose wallets-https://coinsutra.com/best-bitcoin-wallets/
I have my paper wallet with the public and private key but can not figure out how to sweep the bitcoin to my gatehub wallet. I can not remember where I generated the pair. It does have my bitcoin in it when I checked. Do I use the request payment key?
Thank You
Good day. Please can you help me. I have a Nano Ledger Wallet and I am trying to claim my BCH … can you provide me with the right steps to make this happen. Regards
Hi Sudhir,
Just wanted to let you know that your articles are immensely helpful for beginners, seeking investment in crypto-currencies. Thanks for spreading your knowledge.
If I make a purchase with my paper wallet, does the receiver/ and or webpage have my private key from when it was scanned or submitted on a webpage? So would they be able to withdraw the funds if there was a change transaction sent to my paper wallet?
Nope, unless you expose them the private keys of Bitcoin they can’t do anything apart from watching your Bitcoin address on that wallet.
Bro can you help me to get my blockchain’s private key ….I have lost everything, only knows the wallet address
Nope, I can’t help even if I want because I don’t know where you have kept your seed or private keys.
Always use Ledger Nano S like wallets so that you don’t have the headache of taking care of your private keys.
HELLO how can I get a private key cracker tool.
Thanks for a very informative guide. I wonder if these companies and exchanges that keep your wallet and private keys (hopefully safe and secure), if you can request from them they send it to you securely and secretly after completely verifying you are the owner of said wallet. I really think that these companies who are involved in Cryptocurrency and Blockchain would be able to do this, otherwise how can we feel good about putting our FIAT and Crytocurrency into their exchange? Any other thoughts about that? I mean companies are getting hacked and the information obtained is getting spread into the darkweb. How can people feel safe about putting their money into BTC and others if they don’t have assurance that the company protects your private key and that it isn’t stored on a server that is connected to the Internet and has data redundancy to protect from a failure in the system.
@510Finn
That’s why after buying Bitcoins or other Crypto, you transfer it to your own wallet.
@510Finn
Yeah, I have some thoughts on it first is that Bitcoin’s fundamental purpose is not to trust anyone except yourself. If you are trusting exchanges its like you are again trusting a central organization like a bank.
Bitcoin is – BYOB -Be your own Bank, So keep your keys with you with such types of hardware wallets https://coinsutra.com/best-hardware-wallet-bitcoin/
HI. I’ve been confused about basic wallets and how private keys function. Is it right to say that the best way would be to go to bitaddress.org, copy the html and export it to an offline computer where I would generate my OWN public address and private keys only for myself?
I am more interested in a savings type of thing, then when I decide to use some smaller funds for trading/purchase I pick desktop or mobile wallet and send money there, so if ever a disaster comes and wallet folds, i minimize lost coins stored only on that wallet?
@ Gogo
That’s a good idea but still, I will suggest going for Hardware wallets. I am saying this not because paper wallets such as bitaddress.org are not safe but when a future condition like fork lingers on BTC then it might become quite tuff for you to claim both the versions of coins i.e the original and the forked version. As it happened with BTC and BCH. People who kept their BTC in exchanges and paper wallets faced challenges in getting their hands on BCH.
While on the other hand users who were using Hardware wallets like Ledger Nano S were the first one to get their hands on BCH and some even sold it for good profits.
But still choice is yours but I would vote for Ledger Nano S and here is a video series on Ledger Nano S in case you need this-
Does the blockchain.info wallet supply one with private keys for bitcoin . I can see an option to export your ether private key , but cannot see anywhere on how to access my bitcoin private key .
After setting up ones wallet , how does one get or see the private key . Must one first have bitcoin in the wallet before a private key is generated .
I am referring to blockchain.info
hello sir my private key mising please help
@Nanda
Sorry, can’t assist. But if you have seed keys I can tell you depending upon which BIP encrypted it was you can generate your private keys.
Please be aware in the crypto world..if it’s your keys then it’s your coins…Not your keys, not your coins. That’s the same thing mentioned in this article too.
Well explained
How can i access my private key on mycellium wallet?????
@Kavin
This video at CoinSutra’s YouTube Channel explains it well
Hello,
Can you explain what a back up of a private key is?
Does that mean that you store it somewhere safe?
Greetings,
Lennart
@Lennart,
Yes, exactly. Somewhere offline preferably.
Hello,
My question is suppose if I have some bitcoin on my Zebpay wallet or with exchange like Coinsecure which I later transfer to my hardware wallet, wouldn’t I still face the risk of losing my bitcoin in case they(Zebpay, Coinsecure) got hacked cause they provide custodian service which means that they have my private key?
@Gyan
Once you transfer your BTC out from (Zebpay, Coinsecure) to a hardware wallet your private keys will change, which you will control not (Zebpay, Coinsecure) so in short, you will be safe even if they get hacked.
Advice: Do read about private keys and bitcoin wallet on CoinSutra that will help you understand more.
HI Sir,
I have my bitcoins in my blockchain wallet. Is it safe and i have saved my wallet ID and private keys in a word document with a password protected for document and also hardcopy of it. Is it safe to save like this?
Keeping it online in any way or form is not safe and recommended.
However, you can keep it in hardcopy with multiple hardcopy backups.
Please, I don’t know how to transfer from paper wallet to another wallet.
Unless I scan to a cell phone wallet? But on a Trezor, how do I do it?
Thank you!
Try mycelium paired with Trezor you should be able to do that.
PLS, I HAVE A QUESTION I WANT TO ASK… PLS CAN U MAKE A VIDEO REGARDS HOW TO GENERATE PRIVATE KEY AND HOW TO SAVE IT IN AN OFFLINE WALLET TO AVOID THEFT CASE…… BECAUSE AM NEW INTO THIS CRYPTO WORLD….. AND AM USING BLOCKCHAIN WALLET TO KEEP MY BITCOIN WHICH U SAID IS NOT SAFE DUE TO HACKER AND OTHER CYBERCRIMES…………WILL REALLY APPRECIATE IF MY QUESTION/REQUEST IS BEEN ANSWERED…..THANKS…..( [email protected])
@OLOWOTIRIN
Will do something similar on CoinSutra. Thanks for asking.
PLEASE I WANT TO ASK CAN I USE BRAINWALLET.IO TO GENERATE MY PRIVATE KEY FOR MY BITCOIN ON BLOCKCHAIN BECAUSE I WATCH A VIDEO ON YOUTUBE REGARDS IT AND IT WAS AWESOME…….PLS KINDLY REPLY THIS SO I CAN KNOW YOUR STANDS REGARDS IT………THANKS
Thanks. It’s help me a lot!
Glad to know that and do share to teach others too.
So will Digital Wallet Companies decline in popularity and everyone will habe their own paper wallets? What time will the wallets play if they don’t hold your keys ?
Certainly no because paper wallets aren’t easy to use and other question ( What time will the wallets play if they don’t hold your keys ?), I couldn’t understand.
HOW? You mean… scan with Mycellium then send to Trezor…
(sorry, I didn’t use either of them yet)
Thank you, Sudhir!
OR:
with Mycellium I can use scan and transfer the bitcoins from a paper wallet?
Sorry, guess I doubled my question here… Tks
You can scan your paper wallet in Mycelium.
Thanks!!! 🙂
As you know some wallets do not show us the private key like blockchain.info wallet , but I can backup my wallet and so achieve my 12 words (secret phrase) .
I want to know if there is a way which I can convert the secret phrase into my wallet’s private key ?
Glad that you asked this.
Yes, there is a way to see your private keys but handle them with caution.
Use this seed converter and select correct BIP then you will be able to see your private keys.
Let me know your experience once you use it.
Hi… I, like the others, are a relative newbie… so I want to make sure I have this right…
I originally purchased some BTC on Coinbase. Then, in order to participate in the BTG fork, I purchased a Trezor hardware wallet and transferred my BTC to it (no problems).
My question is, am I correct to believe that whenever I want to purchase or sell cryptocurrency, I need to do so on an exchange (like Coinbase) before/after transferring them to my Trezor (creating transaction costs on both ends)?
@Dapper
Yes, thats true.
I am still confused about Trezor. So if you lose your Trezor physical wallet, you can recover it if you kept your 12-24 word recovery code. As I understand it, you buy a new Trezor and then essentially restore it by downloading the private keys from Trezor online Wallet/website. But doesn’t that mean that Trezor.com is holding my private keys all the time? It is a single point of failure, right? If so, then how is Trezor any different from a Coinbase who is storing private keys on behalf of consumers? Trezor is doing the same thing to enable recovery-mode, right?
it is different.
Trezor gives you seed words that only you know. So these are basically your keys where you hold your balance. See our Trezor video tutorials on Youtube for more clarity
Hi and thanks for your trials
My question is about creating a bitcoin wallet;
How I can create web or mobile wallet?
And what I need (knowledge and hardware)
This write-up should help you –https://coinsutra.com/mycelium-bitcoin-wallet/
Also, there are two video tutorials in there that I recommend you to watch.
Hi, I have wallet.dat stored on several USB and SD flash drives and use Bitcoin.qt.
I’m just sitting on the bitcoins at present so will not be actively buying or selling.
I believe these storage devices are not ideal as they can age and corrupt the dat file.
I’m thinking that writing the relevant information to paper may be the best system.
1) I’m reading about deterministic wallets where mnemonic words can be used to reclaim bitcoins.
I cannot find a step by step set of instructions of how to do this. I’m finding loads of deep theory information or just plain dreadful explanations.
Have I understood this correctly? Can a set of words be written down on paper and used to reclaim the bitcoins?
2) Also, is another method to write down the private key and public keys on paper? If so, how are these obtained and then how are they input back into Bitcoin.qt?
3) Also, the dat file was stored on these memory cards before the fork, so I can get hold of bitcoins cash as well.
Do you know of a concise web site I can read? I’m thinking I can sell my bitcoins and bitcoins cash seperately, but I just can’t find out what it is all about.
I’ve even asked exchanges to explain, and get no reply, and they offer no explanation on their web sites either.
4) I have Bitcoin.qt and the up-to-date blockchain on an older, slower computer which I used to make my present dat file. I have just installed Bitcoin-qt on my new super fast computer. Can I just swap the generic dat file with my dat file on the new computer? I encrypted Bitcoin-qt on the older computer. Is the encryption password stored in the wallet.dat file or do I have to feed this into the new Bitcoin-qt installation?
Many thanks for any help.
NN.
This write-up should help you –https://coinsutra.com/mycelium-bitcoin-wallet/
Also, there are two video tutorials in there that I recommend you to watch.
Thanks for the reply. I found your recommended site and videos just confusing as it covers a different wallet, and you ignored items 2, 3 and 4. I guess I’m still searching elsewhere.
Hi. Your article has enlightened me, I’m more or less familiar with cryptology concepts but I’m just starting to explore cryptocurrencies as an investment. I know there is no safe place online, but some are safer than others. Someone recommended me to use uphold.com, so far it seems they don’t expose the private keys to owners (or better-called payers, as the holding company is the one owning/guarding my keys), but I see it is almost the same thing knowing it or not as long as a 3rd party has priv. keys. On the other hand, if I want to sell my BTC dynamically like a trader, then I don’t see a better way to handle it but relying on a web wallet… So, to summarize: 1) would uphold.com be a good choice for a web wallet? 2) in a balance between safety and trading oriented activities, what would be your recommendation? Thanks in advance. PS: have you heard of GTC Digital? I have read good things and bad things about them, but none from impartial sources.
Found a site that lists all private keys:
https://allprivatekeys.herokuapp.com/
Should I be worried? I haven’t searched for my own to see if it’s on there..
The auto-scroll list thing seems to be random…
That’s nonsense. Thanks for telling. Never check your private keys here.
It is red flag.
sir
my old blockchain wallet lost but with backup phrase i created new wallet.
The new wallet has new addresses. The problem is this there is some funds in my old wallet’s imported address now i added old imported address in my new wallet. now show the funds in new wallet but cant transfer any other address please help me i m ready to pay for efforts.
In case of lost private keys or back phrase, we cannot assist you. Thanks